<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>分组选择器</title>
</head>
<body>
<h1>幽灵羊</h1>
<h2>手</h2>
<h3>脚</h3>
<div>嵌套选择器
    <a href="#">点我呀</a>
    <p class="mama">我是你妈妈</p>
    <p>我是你爸爸</p>
</div>
<style>
    h1 ,h2, h3{
        color:green
    }
    div a{
        color:red
    }
    p.mama{
        font-size:18px
    }
</style>
</body>
</html>
